What are inequalities?
Inequalities are the opposite of equations. Equations show when two expressions are EQUAL. Inequalities show when two expressions are NOT EQUAL. If they are not equal, one expression is either greater than or less than the other expression.
How do we write inequalities?
There are 4 different symbols that are used to write inequalities.
1. GREATER THAN is represented by the symbol >
Example: 10 > 7 ("Ten is greater than 7")
2. LESS THAN is represented by the symbol <
Example: 10 < 12 ("Ten is less than 12")
3. GREATER THAN OR EQUAL TO is represented by the symbol >
Example: 8 > 1 ("Eight is greater than or equal to 1") Example: 8 > 8 ("Eight is greater than or equal to 8")
4 LESS THAN OR EQUAL TO is represented by the symbol <
Example: --2 < 0 ("Negative 2 is less than or equal to 0") Example: --2 < --2 ("Negative 2 is less than or equal to negative 2")
TASK: What is the difference between the symbol < and the symbol<?
We can also use variable when we're writing inequalities. We can say at x > 4. This means that x can be any number higher than 4, such as 5, 6, 7, 8,... but it cannot be 4. If we said that x > 4, x could be 4, 5, 6, 7, 8, ...
What can we do with inequalities? Why are they important?
Anything that we can do with a regular (linear) equation, we can also do with an inequality. We can solve them like equations (which we'll talk about in the next lesson) and we can graph them like equations. In fact, there are two ways that we can graph them. We will talk about one way to graph them now and another way to graph them later on in Unit 3.
TASK: Open the page below and watch the video on the first way to graph inequalities-
Inequalities are the opposite of equations. Equations show when two expressions are EQUAL. Inequalities show when two expressions are NOT EQUAL. If they are not equal, one expression is either greater than or less than the other expression.
How do we write inequalities?
There are 4 different symbols that are used to write inequalities.
1. GREATER THAN is represented by the symbol >
Example: 10 > 7 ("Ten is greater than 7")
2. LESS THAN is represented by the symbol <
Example: 10 < 12 ("Ten is less than 12")
3. GREATER THAN OR EQUAL TO is represented by the symbol >
Example: 8 > 1 ("Eight is greater than or equal to 1")
Example: 8 > 8 ("Eight is greater than or equal to 8")
4 LESS THAN OR EQUAL TO is represented by the symbol <
Example: --2 < 0 ("Negative 2 is less than or equal to 0")
Example: --2 < --2 ("Negative 2 is less than or equal to negative 2")
TASK: What is the difference between the symbol < and the symbol < ?
We can also use variable when we're writing inequalities. We can say at x > 4. This means that x can be any number higher than 4, such as 5, 6, 7, 8,... but it cannot be 4. If we said that x > 4, x could be 4, 5, 6, 7, 8, ...
What can we do with inequalities? Why are they important?
Anything that we can do with a regular (linear) equation, we can also do with an inequality. We can solve them like equations (which we'll talk about in the next lesson) and we can graph them like equations. In fact, there are two ways that we can graph them. We will talk about one way to graph them now and another way to graph them later on in Unit 3.
TASK: Open the page below and watch the video on the first way to graph inequalities-
http://www.phschool.com/atschool/academy123/english/academy123_content/wl-book-demo/ph-822s.html
TASK: Answer the 5 questions below:
1.
2. Write an inequality that represents the following statement: a number is less than 6
3. Write the following inequality out in words (What would you say if you were reading the inequality?): x > 18
4. Write the following inequality out in words: 7 > n
5.